$\dfrac{3}{4} + \dfrac{1}{5} = {?}$
Explanation: $ = {\dfrac{3 \times 5}{4 \times 5}} + {\dfrac{1 \times 4}{5 \times 4}} $ $ = {\dfrac{15}{20}} + {\dfrac{4}{20}} $ $ = \dfrac{{15} + {4}}{20} $ $ = \dfrac{19}{20}$